Diagnosis: Adult C. plumbea differ from Boiruna in having dark pigmentation only on the outer lateral tips of the ventral scales; Boiruna has posterior ventrals that are completely covered with dark pigmentation. They may be distinguished from C. clelia by the higher number of ventrals (Appendix 4, Fig. 4) and by the straight line (dentate in C. clelia) on the tips of the ventrals demarking the change between the dark dorsal color and the ivory venter (Fig. 1; Giraudo, 2002). The smallest species (C. bicolor, C. quimi) also have fewer ventrals. Ventral counts for the intermediate-sized form, C. rustica, overlap slightly with counts for C. plumbea (Appendix 4, Fig. 4). Clelia plumbea tends to have a smaller loreal than the other species (Fig. 2B); it was the only species that occasionally lacked a loreal when it was fused with either the posterior nasal or the prefrontal (Appendix 3). In all but one specimen, the loreal was absent or only contacted the second supralabial; in one specimen, the loreal touched supralabials 2 and 3 on both sides of the head. In B. maculata and C. rustica, about half of the loreals contacted one scale and half touched two supralabials; in the rest of the species the loreal always had a joint suture with two or even three supralabials. Hatchling C. plumbea are colored like C. clelia, with a red body, white venter and nape band, and a black dorsal head and neck spot (photograph in Giraudo, 2002; Fig. 10). Ontogentic color changes proceed as in C. clelia. They lack the dark dorsal stripe of B. maculata and C. bicolor, and are not uniformly colored like hatchling C. rustica.